Currently, more and more radar systems are using a phased array antenna, which has a stationary aperture surface, and are configured to run a beam by electronic scanning. Controlling the rotation of the aperture surface to suppress cluttering, to remove jamming, and to suppress the influence of scattering due to electromagnetic waves arriving from a target (Bragg lobe) is therefore not practiced (for example, see Patent Literature 1 for cluttering suppression, Patent Literature 2 for jamming removal, and Patent Literature 3 for Bragg lobe elimination). With the aperture surface used in a stationary state, radar control utilizing the characteristics of polarized waves which are obtained by rotating the aperture surface is also not practiced.
Some phased array antennas use mechanical driving in combination. However, the purpose thereof is to expand the coverage, and the direction of mechanical driving is also limited to an azimuth (AZ) direction in which the coverage is expanded (see Patent Literature 4, for example).